Identification of a potent immunostimulatory oligodeoxynucleotide from Streptococcus thermophilus lacZ

Immunostimulatory sequences of oligodeoxynucleotides (ODNs), such as CpG ODNs, are potent stimulators of innate immunity. Here, we identified a strong immunostimulatory CpG ODN, which we named MsST, from the lac Z gene of Streptococcus (S.) thermophilus ATCC19258, and we evaluated its immune functions. In in vitro studies, MsST had a similar ability as the murine prototype CpG ODN 1555 to induce inflammatory cytokine production and cell proliferation. In mouse splenocytes, MsST increased the number of CD80+CD11c+and CD86+CD11c+ dendritic cells and CD4+CD25+ regulatory T cells. We also analyzed the effects of MsST on the expression of regulatory cytokines by real-time quantitative PCR. MsST was more potent at inducing interleukin-10 expression than the ODN control 1612, indicating that MsST can augment the regulatory T cell response via Toll-like receptor 9, which plays an important role in suppressing T helper type 2 responses. These results suggest that S. thermophilus , whose genes include a strong Immunostimulatory sequence-ODN, is a good candidate for a starter culture to develop new physiologically functional foods and feeds.     

Microbiota analysis of Caspian Sea yogurt, a ropy fermented milk circulated in Japan

We analyzed the microbiota of domestic ropy fermented milk, Caspian Sea yogurt (or 'kasupikai yohguruto' in Japanese), circulated in Japan. We collected six varieties from five localities. Lactococcus ( L) lactis ssp. cremoris was isolated from all samples as the dominant strain at levels of 10⁸−10⁹ CFU/g. We show this strain produces an extracellular polysaccharide (EPS) that causes the unique characteristic viscosity of the product. From analysis of the RAPD pattern of 60 bacterial isolates from the six samples, we found that 59 strains from a total of 60 isolates were identical and produced this viscosity. Furthermore, PFGE analysis of representative strains from each sample indicated that the isolates could be classified into four subgroups. This suggests these L. lactis ssp. cremoris strains found in Caspian Sea yogurt may have been slightly mutated during subculture in Japan. In addition, Lactobacillus (L.) sakei ssp. sakei were isolated from three samples; L. plantarum , Gluconoacetobacter sacchari and Acetobacter aceti were isolated from two samples; and L. paracasei , L. kefiri , Leuconostoc ( Leu. ) mesenteroides were isolated from one sample.     

Effect of ensiled hop (Humulus lupulus L.) residues on plasma acetate turnover rate in sheep

An isotope dilution method using [1‐¹³C]sodium acetate was applied to determine the effect of feeding ensiled hop (Humulus lupulus L.) residues on plasma acetate turnover rate in six adult crossbred sheep. The sheep were fed 63 g/kg body weight (BW)^0.75/day of either mixed hay of orchardgrass (Dactylis glomerata L.) and reed canarygrass (Phalaris arundinacea L.) and round bale silage at 3:1 ratio (Hay‐diet), or another where round bale silage was replaced by ensiled hop residues (Hop‐diet) with a crossover design each of a 3‐week period. The isotope dilution method was performed on day 21 of each dietary treatment. Dry matter digestibility was similar between diets, and nitrogen (N) digestibility was lower (P = 0.001) for Hop‐diet than Hay‐diet. However, N retention did not differ between diets. Plasma acetate concentration was lower (P = 0.04) for Hop‐diet than Hay‐diet, and the turnover rate of plasma acetate did not differ between diets. Plasma concentration of lactate and non‐esterified fatty acids were similar between diets. Hop‐diet was found almost comparable to Hay‐diet on plasma acetate turnover rate in the present experimental conditions. Therefore, it could be concluded that hop residues partially could be used as an alternative to traditionally used round bale silage for rearing sheep.     

DNA methylation analysis on satellite I region in blastocysts obtained from somatic cell cloned cattle

Many observations have been made on cloned embryos and on adult clones by somatic cell nuclear transfer (SCNT), but it is still unclear whether the progeny of cloned animals is presenting normal epigenetic status. Here, in order to accumulate the information for evaluating the normality of cloned cattle, we analyzed the DNA methylation status on satellite I region in blastocysts obtained from cloned cattle. Embryos were produced by artificial insemination (AI) to non‐cloned or cloned dams using semen from non‐cloned or cloned sires. After 7 days of AI, embryos at blastocyst stage were collected by uterine flushing. The DNA methylation levels in embryos obtained by using semen and/or oocytes from cloned cattle were similar to those in in vivo embryos from non‐cloned cattle. In contrast, the DNA methylation levels in SCNT embryos were significantly higher (P < 0.01) than those in in vivo embryos from non‐cloned and cloned cattle, approximately similar to those in somatic cells used as donor cells. Thus, this study provides useful information that epigenetic status may be normal in the progeny of cloned cattle, suggesting the normality of germline cells in cloned cattle.     

中国和日本农业活动对流域氮素收支的影响

To analyze the effect of agricultural activity on nitrogen(N) budget at the watershed scale,a comparative study was conducted at two Japanese watersheds,the Shibetsu River watershed(SRW) and Upper-Naka River watershed(UNRW),and one Chinese watershed,the Jurong Reservoir watershed(JRW).The total area and the proportion of agricultural area(in parentheses) of the watersheds were 685(51%),1 299(21%),and 46 km 2(55%) for SRW,UNRW,and JRW,respectively.The main agricultural land use in SRW was forage grassland,while paddy fields occupied the highest proportion of cropland in UNRW(11% of total area) and JRW(31% of total area).The farmland surplus N was 61,48,and 205 kg N ha 1 year 1 for SRW,UNRW,and JRW,respectively.The total input and output for the whole watershed were 89 and 76,83 and 61,and 353 and 176 kg N ha 1 year 1 for SRW,UNRW,and JRW,respectively.The proportion of discharged N to net anthropogenic N input was 31%,37%,and 1.7% for SRW,UNRW,and JRW,respectively.The two watersheds in Japan showed similar proportions of discharged N to those of previous reports,while the watershed in China(JRW) showed a totally different characteristic compared to previous studies.The high N input in JRW did not increase the amount of discharged N at the outlet of the watershed due to high proportions of paddy fields and water bodies,which was an underestimated N sink at the landscape scale.     

Transport of subarctic large copepods from the Oyashio area to the mixed water region by the coastal Oyashio intrusion

The lateral transport of organic carbon in large grazing copepods ( Neocalanus cristatus, Neocalanus flemingeri, Neocalanus plumchrus and Eucalanus bungii ) from the Oyashio area to the mixed water region (MWR) by the coastal Oyashio intrusion was estimated using the data of VMPS (vertical multiple plankton sampler) and 1500 dbar-referred geostrophic transport from the CTD (conductivity temperature depth sensor) data of five cruises during June 2001 to April 2002 on a repeat observation section OICE (Oyashio Intensive observation line off Cape Erimo), which extends southeastward from Hokkaido Island, Japan. The transport to MWR by the coastal Oyashio intrusion was estimated to be 5.3 × 10¹¹ g C for the four species. Data from profiling floats also indicated that the copepods were advected from OICE to MWR by the coastal Oyashio intrusion within about 2 months. This transport is considered to be one of the significant sources of organic carbon in MWR as it is larger than the amount of large zooplankton consumed by Pacific saury ( Cololabis saira ) in MWR, one of the dominant copepod predators in this region.     

The effects of potato pulp and feeding level of supplements on digestibility, in situ forage degradation and ruminal fermentation in beef steers

Six ruminally cannulated Wagyu (Japanese Black) steers (average initial bodyweight (BW) 387 ± 29 kg) were used in a split‐plot design experiment, comprising a 3 × 3 Latin square design (whole plot) and a randomized block design (subplot). The whole plot treatments were three different feeding levels of supplemental diet, fed at 0.2, 0.4 and 0.6% of BW, on a dry matter (DM) basis. Subplot treatments were two different supplemental diets: a potato pulp silage‐based diet (PPS) and a grain‐based diet (GRAIN). Chopped, medium‐quality cool‐season grass hay (predominately Timothy, Phleum pratense L) was fed daily at 0.7% BW (on a DM basis) as the basal diet. Each period consisted of 21 d, which included 11 d of adaptation to the diets and 10 d of the collection period. Chromium oxide was used as an indigestible marker. In situ forage degradation was measured using the nylon bag technique. The dry matter intake increased (linear; P < 0.01) as the feeding level increased and was not affected by the diet. Digestibility was not affected by any treatments. The GRAIN diet tended to decrease the rate of in situ forage degradation as the feeding level increased, but this trend was not found in the steers fed the PPS diet. Steers fed the GRAIN diet had a lower (P < 0.1) ruminal pH compared with steers fed the PPS diet. Ruminal pH was not significantly affected by feeding level; however, it was numerically higher for steers supplemented at 0.2% per BW than that for the steers supplemented above 0.4% per BW due probably to the higher starch intake. The total volatile fatty acids concentration numerically increased as the feeding level increased and was not affected by the diet. Increasing the feeding level decreased (linear, P < 0.01) the proportion of acetate. Neither diet nor the feeding level had any effects on the proportion of ruminal propionate. The results suggested that, for steers fed the PPS diet, there are not adverse effects on forage digestion in the rumen that occur as the feeding level is increased.